Fluid operated rotary drilling bit



April 18, 1939. J. A. ZUBLIN 2,154,553

FLUID OPERATED RbTARY DRILLING BIT Filed Aug. 29, 1958 w onto 0 JEAN A.Z064 0V,

Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE 18 Claims.

This invention relates to drilling tools, and more particularly to toolsused in the rotary drilling of bore holes, such as oil wells, and stillmore specifically to hydraulic bits of the nature disclosed in my UnitedStates patent application No. 219,357, filed July 15, 1938, entitledCombined fluid and rotary driven drill bits.

In the patent application referred to, utilization is made of the energyin fluid under pressure forced through a drill pipe for rotating therotary cutting elements of the tool, reliance being had upon thereaction of the cutters on the formation to produce a rotation of asupporting member for the cutters. Circulating fluid is caused to issue1 through a plurality of circumferentially spaced nozzles for subsequentaction directly upon the rotary cutter elements themselves, or byindirect action upon these cutters by causing the fluid to be guided bysuitable blades formed on the supporting member or carrier for thecutters.

Limitations in space prevent appropriate positioning of all of thenozzles substantially in a single plane, as disclosed in theaforementioned patent application. The particular drilling tooldescribed therein as a preferred embodiment has approximately one-halfof its cutters in formation contact at any instant of time, the otherhalf being out of contact, or in reserve. Those cutters contacting withthe bottom of the hole are not acted upon during their entire period ofcontact by fluid issuing through the nozzles. There are times when noturning effort is being applied to the cutters to cause their rotation,so that through their reaction with the formation they canassist in therotation of their supporting body or carrier with respect to thesupporting shank.

The overcoming of this difiiculty constitutes one of the objects of thisinvention. Accordingly, one of the features of the invention involves ahydraulic type of drilling bit embodying an improved arrangement ofnozzles in order to obtain a better fluid distribution therethrough foraction upon the roller cutters.

. A further object of the invention is to provide a. hydraulic type ofdrilling bit having a plurality of roller cutters, each cutter beingacted upon with the full orce of a jet of fluid issuing from a singlenozzle or with partial forces of jets issuing from a plurality ofnozzles so as to impart a continuous driving force to each cutter duringthe entire time it is in formation contact.

In the aforementioned application, the main bearing assembly for thecutter supporting body or carrier is complex and relatively difiicult tomanufacture. Accordingly, a further object of the invention resides inan improved bearing assembly for a rotary drilling bit that isrelatively easy to manufacture and put together, and which 1 ispossessed of greater load carrying capacity.

Another object of the invention is to decrease 5 the resistance to flowof fluid through the bearing assembly.

This invention possesses many other advantages and has other objectsthat will become apparent from a consideration of an embodiment of theinvention. For this purpose, a form is shown in the drawing accompanyingand forming part of the present specification, which embodiment will nowbe described in detail, illustrating the general principles of theinvention. However, it is to be understood that this detaileddescription is not to be taken in a limited sense, since the scope ofthe invention is best defined by the ap pended claims.

Referring to the drawing: 20

Figure 1 is an elevation of a combined digging and reaming bit, thedigging portions being shown in section to illustrate details thereof.

Figure 2 is a view of the drill bit taken along the line 2-2 ofFigure 1. 25

Figure 3 is a section taken along the plane 33 of Figure 1.

Figure 4 is an elevation of a modified form of cutter usable in thegeneral tool organization.

In one of its aspects, the invention seeks to overcome the limitationsimposed by the material in a nozzle assembly which prevent uniformdistribution of the nozzles in a single plane in order that the jets offluid can exert their kinetic energy upon the cutters to cause theirrotation at all times while they are in contact with the formation. Thedifliculty noted can be overcome in the specific example shown in thedrawing by providing a staggered arrangement of nozzles consisting of aplurality of rows, the nozzles in each row being substantially in thesame plane. It is desirable that each nozzle be so positioned as todirect the fluid issuing therefrom onto substantially the same parts ofeach roller cutter.

The drilling tool shown is of the composite type described and claimedin my copending applications No. 191,621, filed February 21, 1938 andNo. 218,491, filed July 11, 1938. It consists of a shank Ill having atapered, threaded pin II at one end for its attachment to a string ofdrill pipe (not 50 shown), a reaming portion A, and a digging portion B.The shank has a pair of depending legs l2, I3, one of which I2 ispreferably formed integrally therewith and the other I3 detachablysecured thereto for a purpose that will appear later in the description.The integral leg 12 is provided with an integral transverse extension l4functioning as part of a support for a main hearing sleeve I5 adapted torotatably carry a cutter supporting body or carrier I6 through theintermediation of a plurality of ball bearings l'l rollable incomplementary races l8, l9 formed respectively in the inner surface ofthe carrier and in the external surface of the bearing sleeve. One end20 of the bearingsleeve l5 fits snugly over the integral supportingextension l4, while its other end 2| is piloted into a recess 22provided in the detachable leg l3. Additional support is given thebearing sleeve by inserting therein a plug 23 having a snug sliding fitwith the inner surface l5a of the sleeve 15 and having a reduced outerend portion 23a providing an annular space 24 between it and the innersurfaces of the sleeve and a bore 25 formed at the lower end of thedetachable leg l3.

The carrier [6 is provided with two spaced wall portions 26, 21 betweenwhich extend bearing pins-28 for rotatably mounting the cutters 29. Eachcutter is placed within a recess 30 provided in the carrier, and itsbearing pin 28 inserted through a hole 32 in one of the carrier walls21, through a bore 3| in the cutter and then into a hole 32 in the othercarrier wall 26, after which the bearing pin 28 can be rigidly andsecurely attached to the carrier by welding in material 33 in the holes.With all of the cutters 29 thus mounted on the carrier [6, the lattermember is then placed over the bearing sleeve 15 and the balls I1inserted into the raceways l8, l9 through the holes 34 extending fromthe inner sleeve bore to its external raceway. The cylindrical portions35 of buttons 36 are then inserted in the holes 34 to provide asubstantially continuous raceway on which the bearing balls I! can rolland also to prevent their unwarranted removal from the races. Theassembly including the buttons is then placed over the integralsupporting extension 14 with a rectangular button portion 31 positionedin a keyway 38 cut or otherwise formed in the extension.

The sleeve I5 makes a snug fit with the extension [4 in order that itwill be held in proper alignment therewith. The cooperation between therectangular button portion 31 and the keyway 38 in the extension willprevent rotation between the bearing sleeve l5 and the extension M. Forthe purpose of insuring that such rotation will be impossible ofoccurring, a fillet 39 is welded between the end of the extension andthe beveled surface l5b provided in the bearing sleeve.

Subsequent to the welding in of the fillet, the plug 23 is inserted inthe bearing sleeve bore l5a. This plug is provided with a keyway 40 inwhich a rectangular button portion 31 can be received. Thereafter, thedetachable leg I3 is placed over the end 2| of the bearing sleeve andits upper portion |3a integrated to the shank by welding in material 4|in a groove 42 formed between the end of the leg and the shank.Attachment of the sleeve l5 to this leg can be had by welding inmaterial 24a in the annular groove 24 between the sleeve l5, leg l3 andreduced plug extension 23a.

The cutters 29 are to be rotated by the action of fluid impingingagainst the cutting teeth 29acr against suitable vanes, blades orbuckets that can be attached to the cutters. For this purpose, aplurality of nozzles 43, 44 is provided in the bearing sleeve, beingadapted to direct discharges of fluid against the cutters 29 and alsoagainst the carrier 16 rotatably mounting the cutters. The fluid underpressure will be conveyed from suitable pumps at the surface of the borethrough the usual string of drill pipe to a passageway 45 provided inthe shank and extending into the leg [2 integral with the shank. Fromthis passageway, the fluid can pass through a bore 46 in the bearingsupport l4 and thence into the interior of the bearing sleeve l5, fromwhere it can make its exit through the nozzles 43, 44.

It will be noted that the plug 23 closes one end of the bearing sleeveto prevent leakage of fluid therebeyond and eliminate loss in pressure.In this action the plug is assisted by the welding material 2401. in theannular groove 24. The proper flow between the shank, leg and bearingsleeve is also insured by making the inner bearing sleeve bore [50, ofsubstantially the same diameter as the integral extension bore 46 andalso coaxial therewith.

The positioning of the bearing sleeve 15 over the extension l4 permitsthe provision of a larger sleeve, and consequently, the use of a largerbore I5a therein. A greater volume of fluid with a lesser resistance toits flow can therefore be passed through the sleeve and into the nozzles43, 44, to increase the capacity of the drill bit.

As explained in my application Serial No. 219,- 357, fluid will issuethrough the nozzles 43, 44 and act directly upon the cutter teeth 290.on each cutter 29, causing it to rotate on its bearing pin 28, and byvirtue of its reaction with the formation produce rotation of thecarrier 16 on the main bearing sleeve 15. The fluid from the nozzleswill also act upon blades 41 formed on ribs 48 extending between thecarrier walls 26, 21, which ribs serve to define the recesses 30 inwhich the cutters rotate. This impinging fluid urges carrier rotationwith respect to the shank. From these blades 41, the fluid stream willbe guided onto the teeth or vanes of the cutter portions to assist intheir rotation.

For eflicient operation of the drilling tool. it is essential thatadequate flow occur through each nozzle. Inasmuch as the drilling tooldisclosed is designed to operate similarly to an impulse type of turbineor water wheel, the fluid must have its pressure head changed tovelocity head by causing its rate of flow to accelerate in its passagethrough the nozzles. Thus, the nozzle exit areas 49 are much less thantheir entrance areas 50 which will produce an increase in velocity ofthe fluid passing through the nozzles. It will be noted further that theentrance areas cover a material circumferential extent of the inner boreof the sleeve. This is essential because of the angle at which thenozzles must be placed for efficient and eifective discharge of fluidonto the cutters 29 and the blades 41 formed on the carrier. Because ofthis material circumferential extension of the nozzle entrance area 50,the number of nozzles that can be placed in a single plane on the sleeveis limited to such an extent that fluid issuing under a high velocityfrom the nozzles cannot be acting upon each cutter during its entireperiod of rolling contact with the bottom of the hole, which, in thespecific instance disclosed, will be for about 180 of each completerevolution of the carrier. This difliculty is overcome in accordancewith the present invention by providing a plurality of rows 43, 44 ofnozzles. the nozzles 43 of one row being staggered with respect to thenozzles 44 of another row, and preferably arranged so that there aresubstantially equal circumferential spacings between the nozvirtue ofthis arrangement, assurance is had that one or more jets of fluid willbe acting upon each cutter during its entire contact with the bottom ofthe hole.

The operation of the nozzles, cutters and carrier can possibly be betterunderstood by tracing a cycle through which one of the cutters passes.As seen in Figure 2, the carrier I 6 is rotating clockwise and by reasonof their contact with the formation the cutters 29 will be rotatingcounterclockwise. Fluid issuing from nozzle 44a will first engageagainst the blade 41a formed on the carrier, from which it will beguided and deflected onto the cutter teeth 29a. to cause rotation of thecutter 29. As the carrier continues its rotation, the carrier blade willeventually move out of the line of action of the nozzle 44a which willthen direct the full force of its issuing fluid through the carrierpassageway I60 directly onto the cutter teeth. Continued rotation of thecarrier will eventually move the cutter from the line of action of thenozzle 44a. But before this occurs, fluid ,from the nozzle 43a in theother row {will be directed onto the carrier blade 41a for causingcarrier rotation and also guidance of the fluid onto the cutter teeth.This is aptly illustrated by the relative positions of the nozzles 44aand 43a with respect to the carrier passageway lBd, its blade 41b, andthe cutter 29. In this position, part of the fluid from the nozzle 44ais acting directly upon the cutter teeth and the fluid from the othernozzle 43a is acting directly upon the carrier blade flib, where it willlose part of its kinetic energy, the blade guiding the fluid for actionupon the cutter teeth to which it will impart the remainder of itsenergy. Continued rotation of the carrier will alternately bring thecutter into positions under the other nozzles 44b, 43b, c in which itwill receive the full force of fluid from one of them, and upon movingfrom the line of action of that particular nozzle it will then be actedupon bypartial streams of fluid issuing from more than one nozzle. Thenet result is to provide a more uniform application of fluid energy tothe cutters while they are in formation contact.

After passing through 180 of contact with the formation, each cutterwill leave the hole bottom and pass to an upper position. As there is noneed for rotating the cutters while they are out of formation contact,the upper part Ie of the bearing sleeve I5 is circumferentiallycontinuous, no fluid being permitted to pass to the cutters when in thisposition. This renders the entire fluid pressure available for actionupon the cutters while they are in formation contact.

The nozzles 44 in one row are preferably inclined with respect to thenozzles 43 of the other row, the inclinations 5|, 52 being toward oneanother. This arrangement is preferred because the fluid streams fromboth rows of nozzles will then act upon substantially the same portion29a of each cutter so as to obtain a smoother operation and alsocentralize any erosion on the cutter teeth caused by the fluid jets.

When in operation, the cutters and carrier will be rotated by the actionof the fluid stream. However. the rolling of the cutters on theformation will effect its removal but it will also tend to produce agroove of semi-circular longitudinal section equal in length to theroller cutters. I For the purpose of insuring that a full gauge holewill be produced, the string of drill pipe and the shank attachedthereto are also rotated so that the cutters assume an infinite numberof planes of rotation to provide a corresponding number of semi-circulargrooves which will all combine to produce a hemispherical hole bottom ofthe proper radius. Rotation of the string of drill pipe will alsoprevent its freezing in the bore.

In Figure 4, a modified form of roller cutter is I disclosed, includinga toothed portion 290 and end, disc portions 29b. The fluid dischargesfrom the nozzles will engage the toothed portion 29a to rotate thecutters, as heretofore described, such rotation causing the discs to diginto the formation to out many narrow grooves therein and thereby effectits removal. This type of cutter presents a lesser area to the formationso that it can be penetrated with lighter drilling weights.

The upper part A of the drilling tool constitutes a reamer, described indetail and claimed in my co-pending application Reamer, Serial No. 227,-278, filed August 29, '1938. For the purpose of this application it issufiicient to merely call attention to the reamer roller cutters 55rotatably mounted on the bearing supporting pins 56 welded to the plates51, which, in turn, are welded to the shank Ill. The cutters 55 are keptfree from cuttings by streams of fluid issuing through the nozzles 58communicating with the shank passageway 45.

I claim:

1. In an earth boring apparatus, a shank, cutter means rotatablymounted'on the shank, and

fluid discharge means within the cutter means supported by said shank,said fluid means including a plurality of rows of nozzles adapted todirect their discharges against the same portions of said cutter meansto cause its rotation.

2. An earth boring apparatus as defined in claim 1, the nozzles of onerow being staggered with respect to the nozzles of another row.

3. In an earth boring apparatus, a shank, rotational means including acarrier rotatably mounted on the shank and a plurality of cuttersrotatably mounted on said carrier, and fluid discharge means within thecarrier supported by said shank, said means including a plurality ofcircumferentially arranged rows of nozzles adapted to direct theirdischarges against said rotational means to cause rotation of saidcutters and carrier.

4. An earth boring apparatus as defined in claim 3, the nozzles of onerow being staggered with respect to the nozzles of another row.

5. An earth boring apparatus as defined in claim 3, the nozzles of onerow being staggered with respect to the nozzles of another row, andhaving their lines of action inclined with respect to the lines ofaction of said last-mentioned row of 'nozzles.

6. In an earth boring apparatus, a shank carrying a bearing sleeve, acarrier rotatably mounted on said sleeve, a plurality of cuttersrotatably mounted on said carrier, a fluid pas mounted on said carrier,a fluid passageway in said shank, a fluid passageway in said sleevecommunicating with said shank passageway, and a plurality of nozzlesarranged in rows in the sleeve opening outwardly around the peripherythereof and communicating with its passageway, the nozzles of adjacentrows being staggered with respect to one another and being adapted todirect their discharges against said carrier blades to cause carrierrotation.

8. The combination defined in claim 6, the nozzles of one row beinginclined toward the nozzles of another row in a direction outwardly ofsaid sleeve.

9. The combination defined in claim 7, the nozzles of one row beinginclined toward the nozzles of another row in a direction outwardly ofsaid sleeve.

10. An earth boring tool including a shank having a bearing supportingextension, a bearing sleeve piloted within said shank and encompassingsaid extension, and cutter means rotatably carried by said sleeve.

11. An earth boring tool including a shank having a bearing supportingextension, a bearing sleeve within which said extension is piloted,means within said sleeve for securing it to said shank, and cutter meansrotatably carried by said sleeve.

12. An earth boring tool including a shank having a bearing supportingextension a bearing sleeve piloted within said shank and encompass ingsaid extension, means within said sleeve for securing it to said shank,and cutter means rotatably carried by said sleeve.

13. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve piloted within said shank andencompassing said extension, means including a plug within said sleevefor securing it to said shank, and cutter means rotatably carried bysaid sleeve.

4. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve piloted within said shank andencompassing said extension, means for securing said sleeve to saidextension, means including a plug within said sleeve for securing it tosaid shank, and cutter means "rotatably carried by said sleeve.

15. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve encompassing said extension, saidsleeve having a plurality of raceways thereon, cutter means having aplurality of complementary raceways, rolling bodies in said raceways,means within said sleeve for preventing removal of said rolling bodies,said means securing said sleeve to said extension to prevent itsrotation with respect thereto.

16. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve encompassing said extension, saidsleeve having a plurality of raceways thereon, cutter means having aplurality of complementary raceways, rolling bodies in said raceways,means including a plug within said sleeve for securing it to said shank,means within said sleeve for keying it to said extension, and meanswithin said sleeve for keying it to said plug, both of saidlast-mentioned means extending to said raceways for maintaining saidrolling bodies therein.

17. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve encompassing said extension, cuttermeans rotatably carried by said sleeve, a fluid passageway in said shankand its extension communicating with said hollow bearing sleeve, and aplurality of nozzles in said sleeve extending to its interior, wherebyfiuid discharge from said nozzles against said cutter means will causetheir rotation with respect to said sleeve.

18. An earth boring tool including a shank having a bearing supportingextension, a hollow bearing sleeve encompassing said extension, cuttermeans rotatably carried by said sleeve, a fluid passageway in said shankand extension communicating with said hollow bearing sleeve, a plugclosing the end of said sleeve to prevent leakage therebeyond, and aplurality of nozzles in said sleeve extending to its interior, wherebyfluid discharge from said nozzles against said cutter means will causetheir rotation with respect to said sleeve.

JOHN A. ZUBLIN.

